Struct HttpConfig 

#[non_exhaustive]
pub struct HttpConfig {
    pub bind: SocketAddr,
    pub path: String,
    pub max_request_body_bytes: usize,
    pub max_concurrent_sessions: usize,
}

Available on crate feature transport-http only.

Configuration for the HTTP transport.

Passed inside Transport::Http to control the TCP bind address and the URL path the MCP service is mounted at.

Note on DNS rebinding

rmcp’s StreamableHttpService validates the Host header against an allow-list that defaults to loopback addresses only (localhost, 127.0.0.1, ::1). If you bind to 0.0.0.0 or a non-loopback address, clients must send requests with a Host that matches the allow-list, or use a reverse proxy that rewrites the Host header.

Examples

use std::net::SocketAddr;
use mcpls_core::{HttpConfig, Transport};

let cfg = HttpConfig::new("127.0.0.1:3000".parse().unwrap(), "/mcp");
let transport = Transport::Http(cfg);

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

bind: SocketAddr

TCP address to bind (e.g. 127.0.0.1:3000).

path: String

URL path prefix the MCP service is mounted at (e.g. "/mcp").

max_request_body_bytes: usize

Maximum size, in bytes, of a single POST request body.

Enforced by rmcp’s StreamableHttpService while streaming the body, independent of Content-Length or chunked transfer encoding. Requests exceeding this limit receive 413 Payload Too Large. Defaults to HttpConfig::DEFAULT_MAX_REQUEST_BODY_BYTES (4 MiB), which comfortably covers MCP tool-call request bodies (large results, e.g. from workspace/symbol or bulk edits, are returned in the response, which this limit does not constrain). A value of 0 rejects every POST body.

max_concurrent_sessions: usize

Maximum number of concurrent HTTP sessions.

This is a hard bound, enforced atomically at session creation via a semaphore — never more than this many sessions can be active at once, regardless of request concurrency. Requests that would start a new session beyond this limit receive 429 Too Many Requests. Defaults to HttpConfig::DEFAULT_MAX_CONCURRENT_SESSIONS. A value of 0 rejects every session.

Implementations

impl HttpConfig

pub const DEFAULT_MAX_REQUEST_BODY_BYTES: usize

Default request body size cap (4 MiB), matching rmcp’s own default.

pub const DEFAULT_MAX_CONCURRENT_SESSIONS: usize = 100

Default concurrent HTTP session cap.

pub fn new(bind: SocketAddr, path: impl Into<String>) -> Self

Create an HttpConfig with default body-size and session caps.

Examples

use mcpls_core::HttpConfig;

let cfg = HttpConfig::new("127.0.0.1:3000".parse().unwrap(), "/mcp");

pub const fn with_max_request_body_bytes(self, bytes: usize) -> Self

Override the maximum POST request body size in bytes.

pub const fn with_max_concurrent_sessions(self, max: usize) -> Self

Override the maximum number of concurrent HTTP sessions.

Trait Implementations

impl Clone for HttpConfig

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for HttpConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.